double-digit

The term "double-digit" is a modern English compound formed from two distinct Latin-derived words. "Double" originates from the Latin duplus, meaning "twofold," which itself traces back to the Proto-Indo-European root \dwo-, meaning "two." "Digit" comes from Latin digitus, meaning "finger" or "toe," reflecting the ancient method of counting on one's fingers; this evolved to signify any of the numerals from 0 to 9. The compound logically fuses these concepts: "double" (two) modifies "digit" (a single numeral) to create the meaning "pertaining to a number consisting of two numerals," a concise way to describe figures from 10 to 99. Its usage expanded in the 20th century, particularly in economics and statistics, to describe rates or values within that numerical range.

Structure: double (twofold) + digit (numeral) - double: From Latin duplus (twofold, double). In this compound, it functions as an intensifier/modifier meaning "consisting of two." - digit: From Latin digitus (finger, toe). In this compound, it functions as the core noun meaning "numeral" (from the practice of counting on fingers).